When healing an ally with a staff, all other allies recover 10 HP.
Skillsets that use skill
Baldr's Grace (Full Support)
Shining Time (Offensive Support)
Valkyrie Mist (Full Support)
Dazzling Princess (Team Crippler)
Nordion Hope (Full Support)
Healer of the People (Full Support)
Imbue and Heavenly Light are the two healing specials available in Fire Emblem Heroes. For starters, both are only available on staff-wielders, and are one of the two types of specials available to them (along with the Balm family). Imbue is straightforward, providing a flat increase of 10 HP to the ally receiving healing. Heavenly Light is a bit more complex, instead healing everyone else on the team with the exception of the healed target, for 10 HP. The primary different being that Heavenly Light provides much greater raw healing, but not on the targets that perhaps need them the most.
As these skills can only be run on healers, there is little skill synergy available to them. Imbue however, is a great special to run alongside Live to Serve, as it will grant the wielder with increased healing. This combo serves as a nice compromise between single target and area healing. Heavenly Light’s unlimited range is best suited for teams with units who prefer to go solo, such as mixed teams with a Flier or Cavalry. It’s a great way to mitigate damage from skills such as Savage Blow, keeping the whole team topped up.
Heavenly Light’s healing can sometimes be detrimental to a team’s success. For instance, a unit running HP threshold skills such as Vantage or Desperation may wish to stay below a certain HP threshold. Heavenly Light can overheal the target, disabling the desired skill on the unit. Imbue is the safer option on most teams, accepting the fact that the target of the initial healing is likely the most in need of further healing.